This chapter sketches the historical development of absolute music as both a concept and a specific term. It interrogates the parameters understood to constitute absolute music in the era of tonal common practice. The chapter distinguishes between a Romantic metaphysics of absolute music and empirical or formalist versions. It considers the status of the concept in contemporary scholarship and criticism. In scholarship of the later twentieth century, the two cultures of absolute music yield a new division: the fixed musical text as the autonomous object of musical analysis, as opposed to the open text of cultural-hermeneutic interpretation. The self-sufficiency of absolute music implies a self-sufficiency of aesthetic interest. Upper-case Absolute music, born as it were under the sign of Beethoven's symphonies and E. T. A. Hoffmann's criticism, has thus perhaps always gravitated towards a condition between absolute and program music.